1. Field of the Invention
The present invention relates to an ink print head. More specifically, the present invention discloses an ink print head with low flow resistance central refilling, which provides a wide fluidflowing channel so as to reduce the flow resistance.
2. Description of the Prior Art
Inkjet printers provide high level printing quality for a reasonable price. They have become a welcome printing device in the information age. Striving for higher performance, higher printing quality and quicker printing speed has become a goal of modern research.
Please refer to FIG. 1. FIG. 1 is a diagram of a prior art ink print head 10 of the inkjet printer. During a printing operation, the inkjet printer ejects fluid out from the ink print head 10 onto a printing paper 11. The ink print head 10 comprises an ink container 12 for storing fluid. An ink ejection module 16 is installed on a bottom 14 of the ink container 12 for ejecting the ink out onto the printing paper 11. The printing paper 11 (only a portion is shown in FIG. 1) is set under the ink print head 10. There is a fixed distance 13 between the printing paper 11 and the ink ejection module 16.
Please refer to FIG. 2 to FIG. 4 for a further explanation of the structure of the ink ejection module 16. FIG. 2, FIG. 3, and FIG. 4 offer a perspective view, a structural diagram, and a cross-sectional view along hatched line 4xe2x80x944 of FIG. 2, of the ink ejection module 16, respectively. Please note that, the figures display the ink ejection module 16, which is set on the bottom 14 of the ink container 12. Therefore, FIG. 2, FIG. 3, and FIG. 4 offer a view seen from the bottom of the ink print head 10. In other words, the upper portions of the figures represent the lower portion of the ink print head 10. For simplicity, the ink container 12 is only partially drawn on the figures. A plurality of nozzles 18 is set on the ink ejection module 16, which ejects fluid out onto the printing paper 11 (the printing paper is not shown in FIG. 2 to FIG. 4). The ink ejection module 16 comprises a nozzle plate 20, a dry film 22, and a chip 24, each stacked up. A central slot 30 is set in the middle portion of the chip 24 for passing fluid. A plurality of heaters 32 (providing thermal resistance) is set on the chip 24. In addition, the dry film 22 is stacked on the chip 24. The dry film 22 has a plurality of etching holes, so as to form channels 28 and ink chambers 34 on the chip 24. The nozzle plate 20 is stacked on the dry film 22, yet the nozzles 18 penetrate the nozzle plate 20.
The principle of the prior art ink print head 10 ink ejection module 16 can be described as below. The fluid flows out from the central slot 30 of the chip 24,through the channel 28 that is formed by the dry film 22, and then into the ink chamber 34 which also formed by the dry film 22. The heater 32 of the chip 24 is set corresponding to the ink chambers 34 for heating the fluid inside the ink chambers 34. The fluid then ejects out from the nozzles 18 of the nozzle plate 20 to print on the printing paper 11. A path 35 that fluid flows out from the ink container 12 and ejects out from the nozzles 18 is shown in FIG. 4.
As told before, printing speed requirements of ink printers are increasing constantly. That means the fluid will eject out from the nozzles more and more frequently. In order to resupply the quickly-consumed fluid inside the ink chamber 34, the fluid must able to flow out from the ink container 12, through the channel 28, and into the ink chamber 34 quickly. However, the channel 28 of the prior art ink ejection module 16 is formed only by the thickness of the dry film 22. The thickness of the dry film 22 is about 25 xcexcm. The channel 28 formed by the dry film 22, covering the whole flowing channel from the central slot 30 to the ink chamber 34, is too narrow and too long (about 2 mm). The channel causes a large fluid resistance, so that fluid is unable to flow from the central slot 30 into the ink chamber 34 quickly. Therefore, the prior art ink print head 10 is unable to print quickly.
It is therefore a primary objective of the claimed invention to provide an ink print head with a low flow resistance ink ejection module, overcoming the limitation of the prior art.
The claimed invention, briefly summarized, discloses an ink print head with a low flow resistance ink ejection module. The ink print head has an ink container for storing fluid, a chip installed at a bottom of the ink container having a central slot for passing fluid, and a dry film formed on the chip having a plurality of ink chambers. The ink print head also has a nozzle plate formed below the dry film, a middle portion of the nozzle plate protruding above four sides of the nozzle plate so as to form a central refill chamber, and a near two edges of the nozzle plate having a plurality of nozzles corresponding to the ink chambers of the dry film. In addition, the ink print head also includes a plurality of heaters set on the chip for heating fluid inside the ink chambers so that the fluid can be ejected from the nozzles of the nozzle plate. When operating, fluid inside the ink container will flow through the central slot into the central refill chamber and then into the ink chambers.
It is an advantage of the claimed invention that the central refill chamber increases the capacity and the flow rate of the flowing channel, therefore decreasing the fluid flow resistance. The consumed fluid inside the ink chamber is resupplied quickly, achieving high printing speed.
These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment which is illustrated in the various figures and drawings.